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Diffstat (limited to 'src/users.c')
| -rw-r--r-- | src/users.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/src/users.c b/src/users.c new file mode 100644 index 0000000..dba4701 --- /dev/null +++ b/src/users.c @@ -0,0 +1,154 @@ +/* GNU's users. + Copyright (C) 1992-2005 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + +/* Written by jla; revised by djm */ + +#include <config.h> +#include <getopt.h> +#include <stdio.h> + +#include <sys/types.h> +#include "system.h" + +#include "error.h" +#include "long-options.h" +#include "quote.h" +#include "readutmp.h" + +/* The official name of this program (e.g., no `g' prefix). */ +#define PROGRAM_NAME "users" + +#define AUTHORS "Joseph Arceneaux", "David MacKenzie" + +/* The name this program was run with. */ +char *program_name; + +static int +userid_compare (const void *v_a, const void *v_b) +{ + char **a = (char **) v_a; + char **b = (char **) v_b; + return strcmp (*a, *b); +} + +static void +list_entries_users (size_t n, const STRUCT_UTMP *this) +{ + char **u = xnmalloc (n, sizeof *u); + size_t i; + size_t n_entries = 0; + + while (n--) + { + if (IS_USER_PROCESS (this)) + { + char *trimmed_name; + + trimmed_name = extract_trimmed_name (this); + + u[n_entries] = trimmed_name; + ++n_entries; + } + this++; + } + + qsort (u, n_entries, sizeof (u[0]), userid_compare); + + for (i = 0; i < n_entries; i++) + { + char c = (i < n_entries - 1 ? ' ' : '\n'); + fputs (u[i], stdout); + putchar (c); + } + + for (i = 0; i < n_entries; i++) + free (u[i]); + free (u); +} + +/* Display a list of users on the system, according to utmp file FILENAME. + Use read_utmp OPTIONS to read FILENAME. */ + +static void +users (const char *filename, int options) +{ + size_t n_users; + STRUCT_UTMP *utmp_buf; + + if (read_utmp (filename, &n_users, &utmp_buf, options) != 0) + error (EXIT_FAILURE, errno, "%s", filename); + + list_entries_users (n_users, utmp_buf); + + free (utmp_buf); +} + +void +usage (int status) +{ + if (status != EXIT_SUCCESS) + fprintf (stderr, _("Try `%s --help' for more information.\n"), + program_name); + else + { + printf (_("Usage: %s [OPTION]... [ FILE ]\n"), program_name); + printf (_("\ +Output who is currently logged in according to FILE.\n\ +If FILE is not specified, use %s. %s as FILE is common.\n\ +\n\ +"), + UTMP_FILE, WTMP_FILE); + fputs (HELP_OPTION_DESCRIPTION, stdout); + fputs (VERSION_OPTION_DESCRIPTION, stdout); + printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT); + } + exit (status); +} + +int +main (int argc, char **argv) +{ + initialize_main (&argc, &argv); + program_name = argv[0]; + setlocale (LC_ALL, ""); + bindtextdomain (PACKAGE, LOCALEDIR); + textdomain (PACKAGE); + + atexit (close_stdout); + + parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION, + usage, AUTHORS, (char const *) NULL); + if (getopt_long (argc, argv, "", NULL, NULL) != -1) + usage (EXIT_FAILURE); + + switch (argc - optind) + { + case 0: /* users */ + users (UTMP_FILE, READ_UTMP_CHECK_PIDS); + break; + + case 1: /* users <utmp file> */ + users (argv[optind], 0); + break; + + default: /* lose */ + error (0, 0, _("extra operand %s"), quote (argv[optind + 1])); + usage (EXIT_FAILURE); + } + + exit (EXIT_SUCCESS); +} |